Protein disulphide oxidoreductases in bacteria.

Thioredoxins and eukaryotic protein disulphide isomerases were, until recently, the only enzymes known to catalyse reversible oxidation and reduction of cysteine residues of a wide spectrum of protein substrates. Genetic and biochemical investigations on different bacterial systems have now led to the discovery of novel prokaryotic protein disulphide oxidoreductases that are located either in the periplasm or in the cytoplasmic membrane.